Hypothyroidism
Basic Information
The thyroid gland is a small gland in the neck and has been described as being shaped like a butterfly. Thyroid hormone is responsible for controlling the activity as well as energy use of the body's organs -- in fact, almost every metabolic process is affected by it.
Hypothyroidism is a disorder in which there is a lack of normal thyroid production or secretion of thyroid hormone. In other words, the thyroid gland is underactive so there follows an underproduction of thyroid hormone.
The disorder occurs in nearly 2% of women and only 0.2% of men and although it can occur at any age -- and even though incidence increases with age (past age 60) -- it is screened for in newborns. (An unborn child may be affected if the mother is producing an inadequate secretion of thyroid hormone.)
Other risk factors include obesity, X-ray treatments or after surgery for hyperthyroidism. Usually thyroid-replacement therapy after thyroid surgery or following the destruction of the thyroid gland by radiation is a reasonable preventative measure for hypothyroidism.
There are a number of causes for this disorder. While there are cases of unknown causes, most cases are caused by one or more of the following:
- the result of hyperthyroidism (following the surgical removal of the abnormal thyroid gland)
- abnormal functioning of the body's immune system -- or autoimmune disease -- in which the thyroid gland is attacked
- radiation therapy to the neck
- iodine excess
- iodine deficiency
- following radioactive iodine treatment
- congenital hypothyroidism which occurs in 1 out of 4,000 births
- low activity of the pituitary gland
- suppressed thyroid function from use of drugs such as lithium
Treatment is essential because of complications that may arise if the disorder goes untreated. These include:
- susceptibility to infection
- the risk of myxedema, which is potentially fatal (less common in warm climates)
- infertility
It is necessary to follow up with your health care provider over time to evaluate possible side effects of treatments such as bone demineralization due to over treatment of the disorder or adrenal crisis which can occur with aggressive treatment.
Symptoms
There are many signs and symptoms of this disorder, which is not surprising because, as mentioned above, the thyroid hormone is associated with activity of all of the body's organs. Of course, patients are unlikely to endure all of these symptoms at once. However, most patients will experience at least several of them simultaneously. They include:
- sluggishness or malaise
- tiredness
- feeling weak
- the tendency to gain weight or conversely to have a decrease in appetite and become thin
- retention of fluid, most notably around the eyes
- constipation
- irregular heartbeat -- can be either slow or rapid
- anemia
- menstrual disorders
- coarse, brittle, slow-growing hair
- coarse skin
- chest pain
- dull expression
- slow-moving tongue
- partial eyebrow loss
Children may experience slow growth and mental development while prolonged or untreated hypothyroidism can result in heart failure, severe numbness, swelling and tingling of the hands and feet and even mental retardation in newborns.
Diagnosis/Treatment
Fortunately all of the symptoms listed above can be prevented with proper treatment.
Patients will usually present with some of the symptoms listed above but laboratory blood tests will confirm the diagnosis of hypothyroidism though the tests will not indicate how much thyroid-replacement therapy is necessary.
In treatment, education is important. The patient should be instructed about how to monitor the thyroid disorder, made to understand it is a lifelong treatment, and be made aware of potential health complications associated with it.
Thyroid-replacement therapy has had excellent results and is treated quite easily with synthetic thyroid tablets but it may take a number of months to find the right dosage that works for you. The effectiveness of your dosage can be checked by blood tests. The dose is prescribed daily since the body requires this daily thyroid substance to function efficiently. No side effects occur with the proper dosage but if you stop treatment you may have a relapse. Your dosage may have to be readjusted as your body changes but do not increase or decrease your dosage by yourself as health complications may occur -- always follow through with visits to your health care provider.
Daily activities should go on as usual, with a moderate increase in exercise, only as deemed appropriate by your health care provider. Lose weight if you are overweight. A diet high in fiber is usually recommended.
If you feel you have hypothyroidism or are at risk for or have symptoms of hypothyroidism, please see your health care provider promptly.